Fabrication of superhydrophobic metallic porous surfaces via CO2 and water processing

Superhydrophobic surfaces are of paramount importance for a great number of applications ranging from heat transfer to medicine. However, their mass production is challenging from environmental and scaling points of views. This work proposes a simple, scalable, production method for superhydrophobic surfaces and porous materials. In particular, highly hydrophobic CH2/CH3-grafted copper is achieved via exposure to a high-pressure supercritical CO2 + H2O environment. The hydrophobicity was further reinforced by using hierarchical macronanoporous copper prepared by a simple templating-annealing method reaching a water contact angle of similar to 150 degrees. The grafting is found to be durable in terms of ageing, abrasion and water impact. The superhydrophobic porous material is successfully used to separate oil emulsions from water. Molecular dynamics simulations are employed to investigate the underlying superhydrophobicity mechanisms further. We hypothesise that the obtained grafting results from a CO2 hydrogenation reaction. The proposed approach may pave the way for the mass use of superhydrophobic surfaces and porous materials for anti-corrosion, anti-icing, separation, batteries, sensors, electronic materials, etc.

Automated summary

This study presents a simple and scalable production method for superhydrophobic surfaces and porous materials. The highly hydrophobic CH2/CH3-grafted copper is achieved by exposure to a high-pressure supercritical CO2 + H2O environment, and the hydrophobicity is reinforced by using hierarchical macronanoporous copper. The durable and effective superhydrophobic porous material is successfully utilized for oil-water emulsion separation. Molecular dynamics simulations suggest that the grafting results from a CO2 hydrogenation reaction. The proposed approach may have widespread applications in various fields.